Four related mixed-ligand nickel(II) complexes: effect of steric encumbrance on the structure, DNA/BSA binding, DNA cleavage and cytotoxicity

摘要: Four closely related mononuclear nickel(II) complexes [Ni(L)(diimine)Cl](ClO4) (1–4), where L is a tridentate polypyridyl ligand of 4-methyl-N,N-bis(pyridin-2-ylmethyl)aniline and diimine 2,2′-bipyridine (bpy, 1), 1,10-phenanthroline (phen, 2), dipyrido[3,2-d:20,30-f]quinoxaline (dpq, 3) or dipyrido[3,2-a:20,30-c]phenazine (dppz, 4), have been synthesized characterized using various physico-chemical techniques. All Ni centers adopt distorted octahedral geometry with N5Cl donor sets. From 1 to 4, the dihedral angles between benzene ring plane gradually decline (52.5–6.8°), leading increasing steric encumbrance. The interactions CT-DNA BSA explored absorption emission spectral methods. These display binding propensity in order: 4 (dppz) > 3 (dpq) 2 (phen) (bpy), quenching mechanisms by all are static procedures. In absence any external agents, only (bpy) exhibit apparent DNA cleavage activity, while addition GSH on irradiation UV-A light 365 nm, abilities obviously enhanced, which vary as (GSH) (UV-A). addition, vitro cytotoxicity tumor cells lines (MCF-7, HepG-2 SGC-7901) examined MTT morphological assessment obtained Hoechst 33342 staining reveals that induces apoptosis against HepG-2.